I. Field
The present disclosure relates generally to communication, and more specifically to techniques for performing handoff between wireless communication networks.
II. Background
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, and so on. These wireless networks may be multiple-access networks (or simply, access networks) capable of supporting multiple users by sharing the available resources. Examples of such access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, and Orthogonal Frequency Division Multiple Access (OFDMA) networks.
A user may utilize an access terminal (e.g., a cellular phone) to obtain various communication services. Each service may be satisfactorily provided to the user by ensuring that a specified quality of service (QoS) is achieved for that service. QoS may be quantified by different parameters for different services. For example, a voice service may require a relatively stringent delay and a certain minimum guaranteed data rate whereas a packet data service may require a certain target packet error rate.
An access terminal may perform negotiation with a first access network to obtain the desired QoS for a service. The access terminal may thereafter move into the coverage of a second access network and may be handed off from the first access network to the second access network. The access terminal may need to perform negotiation with the second access network to obtain the desired QoS for the service. In general, the access terminal may perform QoS negotiation for each access network to which the access terminal is handed off. The QoS negotiation with each access network typically requires exchanges of signaling messages between the access terminal and the access network, which consumes valuable radio resources. The QoS negotiation also disrupts service, which may be undesirable for the user.
There is therefore a need in the art for techniques to more efficiently perform handoff between access networks.